(α1S,α4S,α8S)-α,α’,α’’-tris[bis[2-(1,1-dimethylethoxy)-2-oxoethyl]amino]-δ,δ’,δ’’-trioxo-1,4,8,11-tetraazacyclotetradecane-1,4,8-tripentanoic Acid 1,4,8-Tris(1,1-dimethylethyl) Ester is an protected intermediate in the synthesis of chelating agent for fluorescence labeling of histidine-tagged proteins to lipid membranes, which is a powerful mean for studying and monitoring protein interaction in cells.